/Engine/Plugins/Experimental/Mutable/Source/CustomizableObject/Public/MuCO/CustomizableObjectInstanceDescriptor.h
Increases the range of values of the float with ParamName, returns the index of the new float value, -1 otherwise. The added value is not initialized.
int32 AddValueToTextureRange ( const [FString](API\Runtime\Core\Containers\FString) & ParamName )